Can sodium nitrate be used as a replacement for saltpetre?
Yes, sodium nitrate can replace the potassium salt in black powder and many similar mixtures, but in a slightly different ratio. In fact, the “B” grade of commercial blasting powder is made with sodium nitrate, and it’s quite effective. The downside is that sodium nitrate mixtures must be carefully protected from moisture, as they will readily absorb water from the air in humid weather and become useless (Sodium nitrate itself will become damp in humid air, and may even be that way when purchased). Therefore, although it can work, it’s not really practical for most uses.
